


The One and Only Rule in This Grey Jungle

by nsfdoyoung



Series: The Adventures of the Super One Squadron [1]
Category: NCT (Band), SuperM (Korea Band)
Genre: Age Difference, Aged-Up Character(s), Alternate Universe - Non-Famous, Alternate Universe - Not K-Pop Idols, Anal Fingering, Anal Sex, Another series I can't update frequntly, Based on the Super One Project, Beware Mark's Liger Dick, Bottom Lee Donghyuck | Haechan, Dubious Science, Government Experimentation, Human Experimentation, Hybrids, Liger Hybrid Mark, M/M, Mentioned SuperM Ensemble, Mildly Dubious Consent, Minor Huang Ren Jun/Lee Jeno/Na Jaemin, Mutants, Nipple Play, Non-Human Genitalia, Non-Linear Narrative, Scientist Donghyuck, Semi-Public Sex, Song fic, Super Soldier, SuperM are Hybrid Soldiers, Top Mark Lee (NCT), basically they're Captain America but hybrids, because they'll get in trouble, but that's just at the start, non-idols
Language: English
Status: Completed
Published: 2020-10-13
Updated: 2020-10-18
Packaged: 2021-03-07 23:01:53
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 10,915
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26995582
Author URL: https://archiveofourown.org/users/nsfdoyoung/pseuds/nsfdoyoung
Summary: Donghyuck can't believe his double major in Animal Behavior and Zoology with a focus on Felinology led him to this.'This' being sweeping the liger habitat in search of their project's wayward youngest, Subject #SM990802, who everyone calls Mark.Chapter 1: Hyperlink versionChapter 2: Link-less version
Relationships: Lee Donghyuck | Haechan/Mark Lee
Series: The Adventures of the Super One Squadron [1]
Series URL: https://archiveofourown.org/series/1970263
Comments: 18
Kudos: 266





	1. Hyperlink Version

**Author's Note:**

> If you're following me on [Twitter](https://twitter.com/nsfdoyoung), you know that this fic has been in the works since the Tiger Inside MV came out. This is unbetaed as of now, I just needed this out before going to bed, I'll fix everything later, LOL. If you have any questions, drop me a [CC](https://curiouscat.qa/nsfdoyoung). Oh, and the hyperlinks are just wikipedia articles and other related sites or media to help explain the jargon on here; it's all up to you if you read those as you read the fic, read them before reading the fic, or read them after reading the fic. You've no obligation to click on all of them or none at all. You do you, my dudes. And with that, on with the fic!  
> Edit (10-19-20, 3:13 am kst):  
> I've put a link-less version in chapter 2 for those who have issues with hyperlinks, either because of accidental clicking, or because it ruins their reading flow (I personally haven't experienced that so IDRK how distracting it could be to other people). To cater to both types of readers who say "keep them" and "remove them" I just made 2 versions of the same fic.  
> Enjoy, folks!

Donghyuck can't believe his double major in [Animal Behavior](https://en.wikipedia.org/wiki/Ethology) and Zoology with a focus on [Felinology](https://en.wikipedia.org/wiki/Felinology) led him to this.

 _This_ being sweeping the [liger](https://en.wikipedia.org/wiki/Liger) habitat in search of their project's wayward youngest, Subject #SM990802, who everyone calls Mark.

According to the more senior teams, Mark has been increasingly more difficult to handle ever since Donghyuck had been assigned to be Mark's handler, with a team of 5 specialists Donghyuck's age or younger assisting him.

Mark's former handler, Dr Kim Minseok, had been in Discovery and Recruitment since the acquisition of Subject #SM920506, [gaur](https://en.wikipedia.org/wiki/Gaur) hybrid Baekhyun, and Kai the [sloth bear](https://en.wikipedia.org/wiki/Sloth_bear) hybrid, tagged Subject #SM940114. Dr Kim had been with Mark since the subject was acquired for the project, but the senior and his team were eventually returned to their department, and thus Donghyuck and some of the younger specialists were sucked up into the power vacuum, as well as bringing in new people to the project for new needs.

Mark's new handling team needed younger members, anyway; scientists, therapists, and soldiers who are not only brilliant for their age, but physically fit and agile enough to help wrangle and subdue Mark when his instincts overwhelm and get the better of the usually temperate hybrid.

Before being taken into the project, Donghyuck was working in Everland Zoo, with the exact same liger whose genes were used in the experiments with Mark. He was approached, and he accepted. It wasn't only because of the handsome pay; he was also intrigued by the idea of how genes could possibly imbue new feline instincts to a human being. And so, he was tasked to be Mark's new Handler.

As Mark's Handler, Donghyuck studies the feline behavior and instincts Mark has acquired, how he is adapting to these animal traits, and mostly anything to do with the liger side of Mark. He is also acting as Mark's guardian in their headquarters, accepting reports from his team members and the outside Project staff regarding Mark's basic needs, general health, and many other things to make life comfortable for him.

Donghyuck has in his team the Project's current youngest [Epigeneticist](https://en.wikipedia.org/wiki/Epigenetics) Dr Huang Renjun, who mainly monitors how the genetic procedures done to Mark are progressing and affecting him, and if there are any unexpected effects popping up with the manipulation of his phenotype. His findings and reports are used as basis for the procedures that will be received by future subjects the Project will acquire.

Mark's psychiatrist is Dr Zhong Chenle, who is in charge of the hybrid's mental health as a human, learning how he is affected by his circumstances, what he thinks about it, and how he's dealing with his emotions and thoughts, and if needed, prescribe medication for any condition that could be detrimental to Mark's function as a soldier. He also facilitates activities for Mark to pursue hobbies to aid his mental stability.

Dr Na Jaemin is their Physical [Therapist](https://en.wikipedia.org/wiki/Physical_therapy) who handles Mark's physicality, testing his physical limits, helping him on how to adapt to his new physical abilities, and how to take care of his body, like how to help him avoid possible injuries or rehabilitate those Mark receives in operations. He also helps in managing Mark's physical training, and physical maintenance.

Mark's general physician is Dr Park Jisung. He watches over Mark's human health, how his body heals the trauma it receives during training or operations, the changes in diet his body needs, and any illnesses he contracts, and often working closely with Dr Na in maintaining Mark's health through scheduled activities and meal plans. He also treats any injury the members of the team get while dealing with either Mark or the liger's habitat.

Last but not the least is Major Lee Jeno, a military officer transferred from the South Korean Military Special Forces whose official task is Security, to protect their team members and help subdue Mark if he gets overwhelmed or is deemed a threat, as well as to help train the hybrid on the soldier side of the Project. (Unofficially, he's Mark's playmate in the playdates and exercises that Jaemin and Jisung arrange, being the one of their team who is most physically able to keep up with the hybrid.)

The non-combatant members of their handling team were given gun handling and combat training, or else they wouldn't have even been considered in handling an active duty subject, much less the most volatile and experimental one of the bunch.

That's also why there's six of them, compared to the four or five that the other hybrids have on their teams. Sure, it sounds too much to need six late-20s-to-early-30s professionals to wrangle one 21-year old kid, but then again, said 21-year old kid was super-powered and _literally_ armed to the teeth.

Better safe than sorry.

Mark's handling team had to be readjusted to more properly suit his needs after his former handler's transfer, and it seems that the liger is taking his time in adapting to the changes in personnel.

One of the more chatty subjects who regularly interact with Mark, the [snow leopard](https://en.wikipedia.org/wiki/Snow_leopard) hybrid, Subject #SM960701, named Taeyong, thinks Mark might also be undergoing a second puberty after the procedures he received have settled and most, if not all, of his mutations have now manifested.

Being the youngest, having had the most injuries among the candidates during the time of acquisition, and having been the last subject to be taken on for the first batch of trials, Mark was determined by the higher-ups to be the most in-need for multiple procedures, as well as possibly the most susceptible and adaptable to the ensuing mutations.

He came into the operating room a Canadian-Korean orphaned teenager with 3rd-degree burns on over half of his body, and came out a stateless liger hybrid mutant with snow white hair and too many conflicting instincts to handle all by himself.

There's a reason why Mark's the only one in a habitat enclosure and not a suite of rooms like the other six subjects, no matter how unexpected the outcome came out to be.

There was a laundry list of requirements to be chosen for the _Scientific Ubiquitous Protocol Evolution on the Research of Mutants_ Project, or simply referred to as the _SuperM_ Project, a multi-national cooperative program aiming to research and the creation of super soldiers not tethered to just one country, to spearhead international security, cooperation, and peacekeeping efforts all over the world.

The first was that it had to be someone whose circumstances led him to have nowhere to go to but the Project. Meaning: no family, no means to survive on their own, either physically, socially, or economically.

And so the union of governments came to look at hospitals. They looked at the long-term patients, accident survivors, crime victims, indebted patients.

They also checked police and prison records: those with skills that could be useful, who could be reasoned with, who would be desperate to accept the most.

From those, biological testing would be done, to determine if they would be genetically capable of receiving mutations. Blood and other DNA samples will be harvested and put under multiple tests to look for suitable markers and traits. Results from there drastically shrink the pool of candidates.

Psychological tests and interviews are next. These will determine the candidates' views on certain topics, their motivations, their psychological and emotional status.

Basing on those, offers will be made to the most suitable among the unknowing candidates. To those who say no, other positions will be offered according to their skills, experiences, and potentials, including, but not limited to: clerical, facility maintenance, technology development, staff training, security, and subject assistance, therapy, and handling.

This is where Mark's situation strays from protocol.

He didn't get the luxury to say _no_. On the day he was to receive his offer, unexpected complications arose from his injuries and his state deteriorated rapidly.

He fell into a sudden coma.

The higher-ups saw his results as too promising to lose, and made an executive decision to bypass protocol and immediately inducted him into SuperM.

Mark was not supposed to be a part of the first batch of super soldiers that SuperM was to make, but with Mark's sudden downhill, the Project couldn't afford to shelf him, and thus became some sort of limbo, where he received procedures that were modified based on the results of the older subjects, but would become the basis for the next generation of subjects.

The rest of Mark's squadron were crossed with naturally occurring Asian animals: Their [communications](https://en.wikipedia.org/wiki/Military_communications) and [logistics](https://en.wikipedia.org/wiki/Military_logistics) expert, Subject #SH930718, Taemin, the remaining hybrid of the very first stages of proposal testing from SuperM's predecessor, the Shine Project, is a [Komodo dragon](https://en.wikipedia.org/wiki/Komodo_dragon), the aforementioned [squadron leader](https://en.wikipedia.org/wiki/Squadron_leader#Land_forces) and [sniper](https://en.wikipedia.org/wiki/Sniper) gaur Baekhyun, and their [infiltrators](https://en.wikipedia.org/wiki/Infiltration_tactics) sloth bear Kai and snow leopard Taeyong. Ten, Subject #SM960227, is crossed with a [reticulated python](https://en.wikipedia.org/wiki/Reticulated_python) and handles [ammunition](https://en.wikipedia.org/wiki/Ammunition_technical_officer) and [artillery](https://en.wikipedia.org/wiki/Artillery#Crew), while their [reconnaissance](https://en.wikipedia.org/wiki/Reconnaissance) expert, Subject #SM990125, Lucas, is an [Asian elephant](https://en.wikipedia.org/wiki/Asian_elephant). Mark, their main [combat arm](https://en.wikipedia.org/wiki/Combat_Arms), alone was modified with a hybrid animal, the liger.

Mark had been doing well, considering his circumstances, but there will always be things that he'll find difficult to deal with.

Case in point: today.

Mark has been swinging between aggressive and carefree these past few days due to still unknown reasons that Donghyuck and Chenle were still unable to unearth, but he'd never once been unnecessarily violent.

Until now, that is.

Mark had a scheduled skills test today at one of the training rooms with Jaemin and Jisung, and Jeno was requested to assist him, as per usual. Prior to that, the soldier was reporting to Donghyuck regarding Mark's training, watching a video of their latest session on a tablet, their heads close together to avoid missing any details. Donghyuck decided he wanted to oversee the test, and so suggested they continue their meeting on their way there.

They were still not finished with the video when they arrive, so they decided they would continue until Mark gets there. When Mark finally came in, Jeno was at the part of his presentation that he had to point out something on the tablet for Donghyuck's consideration, causing him to come even closer to the Head Handler.

In a blink of an eye, Jeno was gone from the chair beside him. Mark had body slammed him onto the floor. Now, Mark may physically weigh only around 132 pounds or 60 kg, but his genetic modifications granted him the strength of a full grown liger, around 400 lb or 180 kg of force. If Jeno wasn't a more experienced soldier, he would have been crushed. Visually, the major seems to mostly be winded and bruised.

Mark immediately jumped off of Jeno, his face a mix of horror and confusion, before he employed his liger speed to run away from the room.

Jisung and Jaemin rushed to Jeno, treating and stabilizing what they can now before they transfer him to a lab for further check-up.

Donghyuck clicked his tongue, watching them as he accessed their comms.

" _Hulk_ , _Thor_ ," Donghyuck called into his comms, using the themed codenames their team have been assigned. "Where are you guys? _Spider-Man_ attacked _Cap_ unprovoked before fleeing. It's just us three on tracking until _Widow_ and _Hawkeye_ fix _Cap_ up."

It took a moment for him to receive a message.

[ _From:_ **Hulk**

 _Can't; epigen meeting rn. Thor out of HQ_ ]

"Fuck," Donghyuck cursed. "Renjun's in the middle of his epigeneticists' meeting while Chenle's not even here at Headquarters."

"Ask assistance from _Watchtower_ until we're ready?" Jaemin suggested, helping Jeno sit up as Jisung checked his torso for possible broken ribs.

Donghyuck nods, thinking. "Yeah, that'll work."

"Better make it quick, you got that, nerds?" Donghyuck asked, looking at the three on the floor.

Jeno, who was the only one not focused on ensuring his wellbeing, nodded with a pained smile.

"Go get your boy, Hyuck," he still managed to tease despite how his sides must have been screaming in agony.

Donghyuck clicked his tongue in reply, before going after Mark.

Outside the training room, he headed for one of the comms panels embedded to one of the walls.

" _Watchtower_ , this is _Ironman_ speaking," Dongyuck said. " _Spider-Man_ is [AWOL](https://learnersdictionary.com/definition/AWOL) after an altercation with the _Captain_ , who is currently receiving treatment from _Black Widow_ and _Hawkeye_.

" _Thor_ and _Hulk_ are currently on leave. Requesting visuals on _Spider-Man_ , please."

' _Copy, Ironman,_ ' came the reply. ' _Checking surveillance for any possible sightings. Please stay on the line and await further instruction._ '

"Roger," Donghyuck accepted the order.

A few moments later and the speaker crackled. ' _We have visuals._ Spider-Man _was sighted entering his habitat._ '

"Copy that," he replied, acknowledging the information.

' _Do you require assistance from_ Pooh _or_ Rover?'

He considered their offer of lending him Jongin or Taeyong to track Mark down, before dismissing the thought. No need to worry the other hybrids, and afterwards, Mark would feel guilty, thinking he bothered his brothers.

Might as well save the poor guy from more stress-moping later.

"Negative, no assistance needed."

This wasn't the first time Mark ran away from something that will land him in hot shit with Donghyuck, and it definitely won't be the last.

' _Copy. Regardless, backup will be on standby. We at_ Watchtower _wish you success. Over_.'

"Much appreciated. Over."

Conversation over, Donghyuck raced over to one of the exits to get to Mark's sizeable living quarters.

Which is where he is now.

Now, it wouldn't be much of an issue if Mark went directly to the cave in the habitat, but if he decided to lurk among the forestry, then Donghyuck is in for a long search.

Due to it being an actual habitat that could more or less house the actual animal, Mark's habitat is located outside the main building, requiring various flora and sunlight.

It got extended to its current size after the other hybrids often gathered there to play and even train for forest terrain drills, that "Mark's" habitat ended up about the size of two football fields, including the cave that functioned as a building.

The hybrids would tire themselves out during playing or training there that they sometimes refused to return to their own quarters, so Mark's cave was also extended to have a section that's stocked up with [_ibul_ , _yo_](https://kimchimamas.typepad.com/kimchi_mamas/2006/09/yo_traditional_.html), and pillows, as well as a communal shower, with lockers of generic shirts, pants, and other clothes for the other hybrids to use when they get the urge to bother Mark with a sleepover.

They spend so much time there the hybrids often joke that they don't need their own quarters and will just live with Mark permanently instead, which always elicits a warning growl from their youngest, his liger instincts flaring up at the thought of sharing "his territory" with "other males".

Donghyuck plods through a section of the forestry, evading branches and roots that try to hinder him as he makes his way to Mark's cave.

It's times like this that Donghyuck thinks it such a waste that the subjects' trackers don't work inside their facility. The jammers work in keeping infiltrators from tracking the headquarters, but it also hinders them from finding them when the subjects run amok for some reason or another.

Donghyuck is going to petition for alternatives for the subjects next meeting, or at the very least only for Mark, as he is the only one prone to overwhelming instincts when none of the rest of the hybrids seem to.

"Mark!" He calls out, pushing at a low-hanging fern as he walks further into the foliage.

"Come out, Markie, everything's okay!" He shouts, finally finding the mouth of Mark's cave.

He steps inside, his footsteps echoing in the empty space soon enough.

"Jeno's okay, and you know he won't get mad at you," he continues, walking deeper into the dim cave.

He takes a turn, and enters a large, echoing hall. "Come out, everything's okay."

Donghyuck walks deeper into the area. The space makes up half of the cave, with artificial stalactites and stalagmites jutting out everywhere to emulate natural rock formation, cool yet dim blue lighting giving it an eerie feeling.

He reaches the center, where a round [platform](https://www.readdork.com/images/article/Other/_crop1500x1000/superm-sept20.jpg) acts as a sparring ring when the hybrids are training, and as a makeshift stage when the hybrids practice showmanship performances for peacekeeping and charities, a function of the squadron put in place to show that, despite the hybrids being genetically enhanced super soldiers who wouldn't hesitate to kill and be killed for the good of the world, they are still, at their very core, humans who love music and entertainment.

Donghyuck sits down on the edge of the platform and waits.

"Is it really okay, Hyung?" Mark's disembodied voice echoes around Donghyuck.

Since all the hybrids can see in the dark, the lights in the cave are perpetually off. To Donghyuck's regular, unenhanced human eyes, everything is very dim at best, pitch black at most.

Donghyuck can't see Mark, but Mark can definitely see him.

"Yeah, definitely okay," Donghyuck repeats.

He tenses, expecting anything could happen.

As Mark's Head Handler for the past few months, he's learned something about his young charge. He didn't want to take chances.

Mark's big cat instincts to pounce on unsuspecting prey morphed into a habit he does to everyone.

Mark's former handler Dr. Minseok may be both shorter and older than Donghyuck, but he was also a soldier, with a core strong enough to resist falling to the floor when _expecting_ a superpowered manchild try to tackle him to the ground. During Donghyuck's handler Orientation, though, the older had regaled Donghyuck of the many times Mark had caught him unawares that ended up with Dr. Minseok flat on the floor, winded and disoriented.

Donghyuck is a 31-year old professional nerd whose regular exercise consisted of the 10 minute walk from his quarters to his office every day, with the reflexes of an oblivious sloth. If Mark was going to pounce on him, it'll be better for him if he's somewhere that's already close to the ground.

"Come out, kid," Donghyuck calls out, all of his senses on high alert in case Mark tries anything funny.

When Mark does pounce, Donghyuck still doesn't see it coming.

They fall onto the platform, the hybrid sat on Donghyuck's hips, hands pushing down on Donghyuck's shoulders.

"I'm not a kid!" Mark growls, breath washing over Donghyuck's face.

Donghyuck coughs, having his breath knocked out of him.

"I'm ten years... older than you, Mark," Donghyuck manages to get out, untensing to look up at Mark's scowling face hovering over him. "Sometimes… I can't help… but see you as anything else… but a kid."

Mark's frown deepens, before asking: "Will a kid do this?"

"Do wha--"

Donghyuck doesn't manage to finish his question because Mark slams his lips against Donghyuck, his tongue immediately asking permission for entry.

 _OH FUCK_ , Donghyuck's mind shrieks in sudden panic. His body doesn't listen, losing the strength to resist and letting Mark in.

He lets out a whimper when he feels his charge's tongue sweep around his mouth, and hears Mark's responding growl when Donghyuck reciprocates.

"I know, Hyung," Mark whispers against Donghyuck's lips when he pulls back a bit to let his handler breathe.

"I know how you look at me sometimes," Mark continues, rubbing their cheeks together, before snuffling against Donghyuck's face and neck. "I know you don't just see me as a kid, or as a work responsibility when you're monitoring my training or tests and I don't have my shirt on."

"I could just be… looking at Jeno… shirtless next to you, though," Donghyuck teases, a grin making its way onto his lips even as he's breathless from their kiss. It's really not the time to tease, but he's out of his depth, being exposed by Mark like this. He needs time to regroup and get his breathing and pulse back in order.

Mark lets out a snort as he smirks. "As if you would with how Jaemin and Renjun already called dibs on Jeno the first time y'all met."

Donghyuck huffs out a small laugh, head lolling in defeat. "Yeah, I'm not a homewrecker."

Their eyes meet, before something clicks in Donghyuck's brain.

"Is that why you fucking tried to crush Jeno to a pulp earlier?"

A beautiful flush spreads across Mark cheeks, up to his ears, and down his neck. Donghyuck's eyes widen.

"Fuck, is that why you've been cranky the past few days?" Donghyuck demanded, an incredulous smile taking over his face. "Was little Markie jealous that darling Nono's been spending time around me?"

At Mark's growl, Donghyuck, cracks up.

"You know Nana and Junnie already have his dick all tied up for them, right?" He asks, cackling again when Mark's nose crinkles in distaste. Mark dislikes hearing his handlers and squad members cursing, but he himself won't hesitate dropping a _shit_ or a _fuck_ when he screws up.

"Now, lemme up, kid," Donghyuck says, bucking up to try and dislodge Mark. "You have a test to do."

"I'm not a kid!" Mark growls in reply, grinding back in his seat to stop Donghyuck from moving.

Donghyuck feels a bolt of pleasure strike down his spine.

"I won't do that if I were you," he warns the younger, face carefully blank to not make it obvious how he much he liked what Mark is doing.

He realizes it's a moot point when Mark sniffs and smirks down at him.

"Why not, Hyung?" Mark returns, licking at his lips. _Like a predator locked on its prey_. "You smell like you liked it; lots of nice pheromones in the air that I can practically taste it on my tongue."

Without warning, Mark leans down and kisses Donghyuck again. It's more than before: deeper, longer, sweeter; just _more_.

Mark's hands start to wander, from Donghyuck's shoulders, down his chest to squeeze briefly at his chest, sweeping down his sides, to his belt buckle.

"Fuck, Markie," Donghyuck gasps, shivering from the caresses. "Don't."

"Why not?" Mark is growling, deep within his throat, his scowl returning.

"I'm your handler, Mark," Donghyuck says, hands going to his fly to catch Mark's. He squeezes them comfortingly. "Admin's not gonna like me if I let you."

"I'm gonna lose my shit if they try to take you from me," Mark rumbles, his right eye turning golden as his mutations manifest physically in response to his emotional state.

"They're just trying to look out for you." Donghyuck tries to settle him by moving a hand to cup his jaw.

Mark grasps the hand on his face, not wanting to let go. "I want you to look out for me!"

"They're going to think I did something to you," Donghyuck warns.

Yes, he admits, he's wanted Mark the moment he realized he wants to monitor all of Mark's training sessions personally less because of scientific reasons and more because he wants to see Mark do superhuman feats without his shirt on, all of his compact muscles all sweaty and on display.

He expects Mark to give up, or maybe whine out another flimsy excuse. He's not expecting what Mark says next.

"Dad can vouch for you, Hyung," Mark purrs, rubbing his face against Donghyuck's hand. "He can tell them you didn't do anything to me."

Donghyuck's eyes narrow. "What the fuck have you been telling Dr Minseok, twerp?"

"Nothing," Mark hedges. "But he kept asking me why I suddenly seem to always lose my shirt during training."

He cringes when his canines suddenly drop. "And why, when we were at the pool on you guys' first monthsary, my teeth came out when you took your shirt off to swim."

"Oh, Markie likes tits, then?" Donghyuck latches on, not being able to stop himself from teasing Mark when the opportunity arises.

"I like _your_ tits," Mark shoots back, growl returning to his voice. "They look puffy and squishy."

"Insulting me won't make me want to put your dick in my ass, brat," Donghyuck retorts, but he's smiling.

"So you've had a crush on me that long?"

"I smelled your arousal the first day we met before Dad said I was 21," Mark replies, face unimpressed. "What do you say about that, Hyung?"

"Is that why you kept stretching your jaw with your mouth open the day we met? A fucking [Flehmen response](https://www.grantatkinson.com/blog/understanding-flehmen-in-big-cats)?" Donghyuck asks, looking up at Mark in surprise. "You were sniffing me for pheromones?" At Mark's embarrassed nod, Donghyuck flops his head back onto the ground.

"I haven't gotten laid properly since I got employed here if I'm seriously considering letting you near my ass right now," Donghyuck sighs.

Mark smirks and grinds down on him again, and Donghyuck lets out a groan. "That's unfair, brat."

"You think that's unfair? I'll show you unfair."

Mark gets off him and the platform, but doesn't go far. He moves to kneel between Donghyuck's legs and pulls him by the hips further onto the edge so his ass hangs off the platform, his thighs braced over Mark's as the liger hybrid grinds against his ass.

"Fuck, Mark!" Donghyuck hisses, hands flying to Mark's face to pull him down for a kiss.

He can't believe he's doing this.

He's supposed to be Mark's guardian, and yet, here he is, about to let his charge into his pants. It's definitely, absolutely irresponsible and unprofessional and probably morally gray with their ten-year age gap, but one of Mark's hands drift up to twist one of Donghyuck's nipples as he grinds his filling, large cock against Donghyuck's ass, and it's all he can do to keep breathing.

Donghyuck keeps muttering curses under his breath as he tries to pull off his pants off. Mark gets the idea and helps him, pulling off Donghyuck's slacks, boxer briefs, and loafers off on one hard tug, leaving his lower half naked save his low-cut socks.

Mark stuffs a hand in his joggers' pocket and pulls out something Donghyuck doesn't see properly. He then unties his joggers and pulls them low enough around his thighs to have his cock pop up, the waist band going just past his balls.

Donghyuck stares at Mark's cock. He'd speculated and hoped, but he hadn't been able to confirm if Mark's cock had the stereotypical feline [penile spines](https://en.wikipedia.org/wiki/Penile_spines) until now. He never thought he'd be into this kind of shit, but the more you know, he guesses. God, those would probably make his insides feel _so good_ later on.

Donghyuck lays back down as he pulls his shirt and tucks it under his chin.

"Better make it quick. Markie, before I change my mind."

In response, the click of a bottle rings in the air, and Donghyuck realizes that what Mark pulled out from his pocket was probably a bottle of oil or lotion to use as lube.

"You little fucker, did you plan this?" Donghyuck demands, sitting back up to look at Mark's guilty face.

He loses strength in his arms and falls back down when Mark inserts two slick fingers into him.

"Maybe?" Mark admits, dragging his fingers in and out to spread the lubricant, before hunting around for Donghyuck's prostate. "I know you usually jack off on your day off, which was yesterday, and I'm pretty sure I saw you limping a bit while you were looking for me."

"Fuck, you little stalker, I can't believe you know this," Donghyuck lets out a little incredulous laugh, before letting out a pleasured moan. "You're lucky I was in the mood to ride my dildo in the shower today."

 _"Fuck_ ," Mark growls, before pulling his fingers out and slamming his spiny hybrid cock deep into Donghyuck's ass.

Donghyuck gasps, feeling how Mark's thick cock splits him open, Mark's spines raking against his walls every time Mark pulls back to push into him again.

He pulls Mark back down for a kiss, and Mark redoubles his efforts to rearrange Donghyuck's insides as their tongues battle it out.

Suddenly, Donghyuck's communicator crackles to life.

'Ironman _? It's_ Hulk _. Where the fuck are you?_ '

Holy fuck, it's Renjun. Donghyuck is dead if he ignores him.

He tries to stop Mark fucking into him, just until he finishes talking to Renjun, but the hybrid won't hear of it. He wraps his arms around Donghyuck's middle and keeps his pace, tucking his head against his handler's collarbones.

"This--This is _Iron-Ironman_ …" Donghyuck stutters out, trying to keep his composure.

' _You found him?_ ' Comes Renjun's impatient demand.

"Yeah… Yeah, I-ah! I've got-- I've got him," Donghyuck replies through grit teeth as Mark keeps hitting his prostate spot on.

' _Why do you--_ ' Renjun cuts off, before gasping.

' _Disgusting,_ ' he suddenly hisses. ' _The moment I see you, I'm gonna kill you. Over and out._ '

"Fuck, he knows," Donghyuck ekes out. This seems to spur Mark on, because he curses before going back up to meet Donghyuck's lips in a deep kiss.

They're too wound up to make it last. When Mark pulls away to dive down to Donghyuck's chest, teething at his nipples with those sharp canines, Donghyuck can't stop the wave of pleasure of his orgasm taking over him. He spills across both their stomachs, and Mark thrusts even faster and deeper than Donghyuck thought was possible.

Mark cums deep inside Donghyuck's guts, the way his spikes drag against his insides feeding into his orgasm.

When they both catch their breaths, Mark pulls out slow and steady. His spines have softened enough that they hopefully won't deal Donghyuck more damage than they already have.

Mark kneels against the edge of the platform, pulling Donghyuck up to sit on his slanted thighs. Mark rubs his face against Donghyuck again, and the older lets him, hands caressing the younger's dyed red hair fondly.

"Thank God you have a huge shower and a locker room," Donghyuck rasps against Mark's lips, stealing a quick kiss.

When they make their way out of Mark's habitat, they see their entire handling team camped out on the entrance, sitting on the floor or leaning on the walls in wait.

The moment Renjun catches sight of them, he gets up from his place on the floor next to Jeno and Jaemin to charge out at them accusingly.

"I can't believe you!" He says, voice shrill. _"_ He's a _child_! _"_

"He's legal," Donghyuck replies, trying to calm his colleague. "He's twenty-one."

"He's ten years younger than you!" Renjun continues, reaching a hand over to grab Donghyuck.

Mark cuts in between them suddenly, his right eye burning gold, canines out as he growls at Renjun. Jisung and Chenle scramble to pull Renjun back away from Mark as Jaemin helps Jeno up from sitting on the floor. Donghyuck looks back helplessly at them from behind the hybrid.

"Step away, Ge," Mark warns, voice gravelly. "I don't want to hurt any of you again."

As the rest of them keep their distance, Mark finally deems everything safe, and he returns back to normal. He's clear-headed enough that he finally looks somewhat sheepish.

"Sorry."

"What are we telling Dr Kim?" Chenle asks, eyes narrowed. Donghyuck knows his brain is running countless speculations by now.

"He kinda already knows?" Mark offers.

Renjun rolls his eyes in exasperation. "God, whatever."

He turns around and latches onto Jeno's arm that wasn't already held by Jaemin.

"Hyuck's not the only one who's going to get dicked down today," he says, pulling Jeno, and by extension Jaemin, back inside Headquarters.

"Jisung, reschedule your test to another day, because Jeno and Jaemin won't be able to move properly tomorrow."

"Hyung, you're gross, too," Jisung whines behind them, Chenle laughing next to him as they follow the three inside.

"So, what now?" Donghyuck says. He's got Mark wrapped around him as they stay behind at the entrance to Mark's habitat.

"I'm gonna ask Dad if he can be the one to tell the Higher Ups about the status update," Mark sighs out, obviously not thrilled with the absolute clusterfuck informing Admin about them will be. Donghyuck pets at his head to try and keep him calm.

"What about your hyungs?" Donghyuck asks, referring to Mark's squadron. "Are you going to tell them about us?"

"Oh, they definitely know I like you," Mark cringes, curling deeper into Donghyuck's side. "They're gonna be insufferable, oh my God!"

"Better clean up the stage now before you guys do any sparring or practicing tomorrow, then," Donghyuck says, pulling Mark up to leave a kiss on his forehead before stepping away and following his team inside.

"I'll be waiting in my room once you're done, okay?" Donghyuck calls over his shoulder, hand waving goodbye. "I need you to drill me into my mattress before your curfew, baby, so chop-chop!"


	2. Link-less Version

**Summary for the Chapter:**

> The same contents, just without the hyperlinks for those who keep accidentally clicking or get distracted by the different color and underline.

Donghyuck can't believe his double major in Animal Behavior and Zoology with a focus on Felinology led him to this.

 _This_ being sweeping the liger habitat in search of their project's wayward youngest, Subject #SM990802, who everyone calls Mark.

According to the more senior teams, Mark has been increasingly more difficult to handle ever since Donghyuck had been assigned to be Mark's handler, with a team of 5 specialists Donghyuck's age or younger assisting him.

Mark's former handler, Dr Kim Minseok, had been in Discovery and Recruitment since the acquisition of Subject #SM920506, gaur hybrid Baekhyun, and Kai the sloth bear hybrid, tagged Subject #SM940114. Dr Kim had been with Mark since the subject was acquired for the project, but the senior and his team were eventually returned to their department, and thus Donghyuck and some of the younger specialists were sucked up into the power vacuum, as well as bringing in new people to the project for new needs.

Mark's new handling team needed younger members, anyway; scientists, therapists, and soldiers who are not only brilliant for their age, but physically fit and agile enough to help wrangle and subdue Mark when his instincts overwhelm and get the better of the usually temperate hybrid.

Before being taken into the project, Donghyuck was working in Everland Zoo, with the exact same liger whose genes were used in the experiments with Mark. He was approached, and he accepted. It wasn't only because of the handsome pay; he was also intrigued by the idea of how genes could possibly imbue new feline instincts to a human being. And so, he was tasked to be Mark's new Handler.

As Mark's Handler, Donghyuck studies the feline behavior and instincts Mark has acquired, how he is adapting to these animal traits, and mostly anything to do with the liger side of Mark. He is also acting as Mark's guardian in their headquarters, accepting reports from his team members and the outside Project staff regarding Mark's basic needs, general health, and many other things to make life comfortable for him.

Donghyuck has in his team the Project's current youngest Epigeneticist Dr Huang Renjun, who mainly monitors how the genetic procedures done to Mark are progressing and affecting him, and if there are any unexpected effects popping up with the manipulation of his phenotype. His findings and reports are used as basis for the procedures that will be received by future subjects the Project will acquire.

Mark's psychiatrist is Dr Zhong Chenle, who is in charge of the hybrid's mental health as a human, learning how he is affected by his circumstances, what he thinks about it, and how he's dealing with his emotions and thoughts, and if needed, prescribe medication for any condition that could be detrimental to Mark's function as a soldier. He also facilitates activities for Mark to pursue hobbies to aid his mental stability.

Dr Na Jaemin is their Physical Therapist who handles Mark's physicality, testing his physical limits, helping him on how to adapt to his new physical abilities, and how to take care of his body, like how to help him avoid possible injuries or rehabilitate those Mark receives in operations. He also helps in managing Mark's physical training, and physical maintenance.

Mark's general physician is Dr Park Jisung. He watches over Mark's human health, how his body heals the trauma it receives during training or operations, the changes in diet his body needs, and any illnesses he contracts, and often working closely with Dr Na in maintaining Mark's health through scheduled activities and meal plans. He also treats any injury the members of the team get while dealing with either Mark or the liger's habitat.

Last but not the least is Major Lee Jeno, a military officer transferred from the South Korean Military Special Forces whose official task is Security, to protect their team members and help subdue Mark if he gets overwhelmed or is deemed a threat, as well as to help train the hybrid on the soldier side of the Project. (Unofficially, he's Mark's playmate in the playdates and exercises that Jaemin and Jisung arrange, being the one of their team who is most physically able to keep up with the hybrid.)

The non-combatant members of their handling team were given gun handling and combat training, or else they wouldn't have even been considered in handling an active duty subject, much less the most volatile and experimental one of the bunch.

That's also why there's six of them, compared to the four or five that the other hybrids have on their teams. Sure, it sounds too much to need six late-20s-to-early-30s professionals to wrangle one 21-year old kid, but then again, said 21-year old kid was super-powered and _literally_ armed to the teeth.

Better safe than sorry.

Mark's handling team had to be readjusted to more properly suit his needs after his former handler's transfer, and it seems that the liger is taking his time in adapting to the changes in personnel.

One of the more chatty subjects who regularly interact with Mark, the snow leopard hybrid, Subject #SM960701, named Taeyong, thinks Mark might also be undergoing a second puberty after the procedures he received have settled and most, if not all, of his mutations have now manifested.

Being the youngest, having had the most injuries among the candidates during the time of acquisition, and having been the last subject to be taken on for the first batch of trials, Mark was determined by the higher-ups to be the most in-need for multiple procedures, as well as possibly the most susceptible and adaptable to the ensuing mutations.

He came into the operating room a Canadian-Korean orphaned teenager with 3rd-degree burns on over half of his body, and came out a stateless liger hybrid mutant with snow white hair and too many conflicting instincts to handle all by himself.

There's a reason why Mark's the only one in a habitat enclosure and not a suite of rooms like the other six subjects, no matter how unexpected the outcome came out to be.

There was a laundry list of requirements to be chosen for the _Scientific Ubiquitous Protocol Evolution on the Research of Mutants_ Project, or simply referred to as the _SuperM_ Project, a multi-national cooperative program aiming to research and the creation of super soldiers not tethered to just one country, to spearhead international security, cooperation, and peacekeeping efforts all over the world.

The first was that it had to be someone whose circumstances led him to have nowhere to go to but the Project. Meaning: no family, no means to survive on their own, either physically, socially, or economically.

And so the union of governments came to look at hospitals. They looked at the long-term patients, accident survivors, crime victims, indebted patients.

They also checked police and prison records: those with skills that could be useful, who could be reasoned with, who would be desperate to accept the most.

From those, biological testing would be done, to determine if they would be genetically capable of receiving mutations. Blood and other DNA samples will be harvested and put under multiple tests to look for suitable markers and traits. Results from there drastically shrink the pool of candidates.

Psychological tests and interviews are next. These will determine the candidates' views on certain topics, their motivations, their psychological and emotional status.

Basing on those, offers will be made to the most suitable among the unknowing candidates. To those who say no, other positions will be offered according to their skills, experiences, and potentials, including, but not limited to: clerical, facility maintenance, technology development, staff training, security, and subject assistance, therapy, and handling.

This is where Mark's situation strays from protocol.

He didn't get the luxury to say _no_. On the day he was to receive his offer, unexpected complications arose from his injuries and his state deteriorated rapidly.

He fell into a sudden coma.

The higher-ups saw his results as too promising to lose, and made an executive decision to bypass protocol and immediately inducted him into SuperM.

Mark was not supposed to be a part of the first batch of super soldiers that SuperM was to make, but with Mark's sudden downhill, the Project couldn't afford to shelf him, and thus became some sort of limbo, where he received procedures that were modified based on the results of the older subjects, but would become the basis for the next generation of subjects.

The rest of Mark's squadron were crossed with naturally occurring Asian animals: Their communications and logistics expert, Subject #SH930718, Taemin, the remaining hybrid of the very first stages of proposal testing from SuperM's predecessor, the Shine Project, is a Komodo dragon, the aforementioned squadron leader and sniper gaur Baekhyun, and their infiltrators sloth bear Kai and snow leopard Taeyong. Ten, Subject #SM960227, is crossed with a reticulated python and handles ammunition and artillery, while their reconnaissance expert, Subject #SM990125, Lucas, is an Asian elephant. Mark, their main combat arm, alone was modified with a hybrid animal, the liger.

Mark had been doing well, considering his circumstances, but there will always be things that he'll find difficult to deal with.

Case in point: today.

Mark has been swinging between aggressive and carefree these past few days due to still unknown reasons that Donghyuck and Chenle were still unable to unearth, but he'd never once been unnecessarily violent.

Until now, that is.

Mark had a scheduled skills test today at one of the training rooms with Jaemin and Jisung, and Jeno was requested to assist him, as per usual. Prior to that, the soldier was reporting to Donghyuck regarding Mark's training, watching a video of their latest session on a tablet, their heads close together to avoid missing any details. Donghyuck decided he wanted to oversee the test, and so suggested they continue their meeting on their way there.

They were still not finished with the video when they arrive, so they decided they would continue until Mark gets there. When Mark finally came in, Jeno was at the part of his presentation that he had to point out something on the tablet for Donghyuck's consideration, causing him to come even closer to the Head Handler.

In a blink of an eye, Jeno was gone from the chair beside him. Mark had body slammed him onto the floor. Now, Mark may physically weigh only around 132 pounds or 60 kg, but his genetic modifications granted him the strength of a full grown liger, around 400 lb or 180 kg of force. If Jeno wasn't a more experienced soldier, he would have been crushed. Visually, the major seems to mostly be winded and bruised.

Mark immediately jumped off of Jeno, his face a mix of horror and confusion, before he employed his liger speed to run away from the room.

Jisung and Jaemin rushed to Jeno, treating and stabilizing what they can now before they transfer him to a lab for further check-up.

Donghyuck clicked his tongue, watching them as he accessed their comms.

" _Hulk_ , _Thor_ ," Donghyuck called into his comms, using the themed codenames their team have been assigned. "Where are you guys? _Spider-Man_ attacked _Cap_ unprovoked before fleeing. It's just us three on tracking until _Widow_ and _Hawkeye_ fix _Cap_ up."

It took a moment for him to receive a message.

[ _From:_ **Hulk**

 _Can't; epigen meeting rn. Thor out of HQ_ ]

"Fuck," Donghyuck cursed. "Renjun's in the middle of his epigeneticists' meeting while Chenle's not even here at Headquarters."

"Ask assistance from _Watchtower_ until we're ready?" Jaemin suggested, helping Jeno sit up as Jisung checked his torso for possible broken ribs.

Donghyuck nods, thinking. "Yeah, that'll work."

"Better make it quick, you got that, nerds?" Donghyuck asked, looking at the three on the floor.

Jeno, who was the only one not focused on ensuring his wellbeing, nodded with a pained smile.

"Go get your boy, Hyuck," he still managed to tease despite how his sides must have been screaming in agony.

Donghyuck clicked his tongue in reply, before going after Mark.

Outside the training room, he headed for one of the comms panels embedded to one of the walls.

" _Watchtower_ , this is _Ironman_ speaking," Dongyuck said. " _Spider-Man_ is AWOL after an altercation with the _Captain_ , who is currently receiving treatment from _Black Widow_ and _Hawkeye_.

" _Thor_ and _Hulk_ are currently on leave. Requesting visuals on _Spider-Man_ , please."

' _Copy, Ironman,_ ' came the reply. ' _Checking surveillance for any possible sightings. Please stay on the line and await further instruction._ '

"Roger," Donghyuck accepted the order.

A few moments later and the speaker crackled. ' _We have visuals._ Spider-Man _was sighted entering his habitat._ '

"Copy that," he replied, acknowledging the information.

' _Do you require assistance from_ Pooh _or_ Rover?'

He considered their offer of lending him Jongin or Taeyong to track Mark down, before dismissing the thought. No need to worry the other hybrids, and afterwards, Mark would feel guilty, thinking he bothered his brothers.

Might as well save the poor guy from more stress-moping later.

"Negative, no assistance needed."

This wasn't the first time Mark ran away from something that will land him in hot shit with Donghyuck, and it definitely won't be the last.

' _Copy. Regardless, backup will be on standby. We at_ Watchtower _wish you success. Over_.'

"Much appreciated. Over."

Conversation over, Donghyuck raced over to one of the exits to get to Mark's sizeable living quarters.

Which is where he is now.

Now, it wouldn't be much of an issue if Mark went directly to the cave in the habitat, but if he decided to lurk among the forestry, then Donghyuck is in for a long search.

Due to it being an actual habitat that could more or less house the actual animal, Mark's habitat is located outside the main building, requiring various flora and sunlight.

It got extended to its current size after the other hybrids often gathered there to play and even train for forest terrain drills, that "Mark's" habitat ended up about the size of two football fields, including the cave that functioned as a building.

The hybrids would tire themselves out during playing or training there that they sometimes refused to return to their own quarters, so Mark's cave was also extended to have a section that's stocked up with quilts, floor mattresses, and pillows, as well as a communal shower, with lockers of generic shirts, pants, and other clothes for the other hybrids to use when they get the urge to bother Mark with a sleepover.

They spend so much time there the hybrids often joke that they don't need their own quarters and will just live with Mark permanently instead, which always elicits a warning growl from their youngest, his liger instincts flaring up at the thought of sharing "his territory" with "other males".

Donghyuck plods through a section of the forestry, evading branches and roots that try to hinder him as he makes his way to Mark's cave.

It's times like this that Donghyuck thinks it such a waste that the subjects' trackers don't work inside their facility. The jammers work in keeping infiltrators from tracking the headquarters, but it also hinders them from finding them when the subjects run amok for some reason or another.

Donghyuck is going to petition for alternatives for the subjects next meeting, or at the very least only for Mark, as he is the only one prone to overwhelming instincts when none of the rest of the hybrids seem to.

"Mark!" He calls out, pushing at a low-hanging fern as he walks further into the foliage.

"Come out, Markie, everything's okay!" He shouts, finally finding the mouth of Mark's cave.

He steps inside, his footsteps echoing in the empty space soon enough.

"Jeno's okay, and you know he won't get mad at you," he continues, walking deeper into the dim cave.

He takes a turn, and enters a large, echoing hall. "Come out, everything's okay."

Donghyuck walks deeper into the area. The space makes up half of the cave, with artificial stalactites and stalagmites jutting out everywhere to emulate natural rock formation, cool yet dim blue lighting giving it an eerie feeling.

He reaches the center, where a round platform acts as a sparring ring when the hybrids are training, and as a makeshift stage when the hybrids practice showmanship performances for peacekeeping and charities, a function of the squadron put in place to show that, despite the hybrids being genetically enhanced super soldiers who wouldn't hesitate to kill and be killed for the good of the world, they are still, at their very core, humans who love music and entertainment.

Donghyuck sits down on the edge of the platform and waits.

"Is it really okay, Hyung?" Mark's disembodied voice echoes around Donghyuck.

Since all the hybrids can see in the dark, the lights in the cave are perpetually off. To Donghyuck's regular, unenhanced human eyes, everything is very dim at best, pitch black at most.

Donghyuck can't see Mark, but Mark can definitely see him.

"Yeah, definitely okay," Donghyuck repeats.

He tenses, expecting anything could happen.

As Mark's Head Handler for the past few months, he's learned something about his young charge. He didn't want to take chances.

Mark's big cat instincts to pounce on unsuspecting prey morphed into a habit he does to everyone.

Mark's former handler Dr. Minseok may be both shorter and older than Donghyuck, but he was also a soldier, with a core strong enough to resist falling to the floor when _expecting_ a superpowered manchild try to tackle him to the ground. During Donghyuck's handler Orientation, though, the older had regaled Donghyuck of the many times Mark had caught him unawares that ended up with Dr. Minseok flat on the floor, winded and disoriented.

Donghyuck is a 31-year old professional nerd whose regular exercise consisted of the 10 minute walk from his quarters to his office every day, with the reflexes of an oblivious sloth. If Mark was going to pounce on him, it'll be better for him if he's somewhere that's already close to the ground.

"Come out, kid," Donghyuck calls out, all of his senses on high alert in case Mark tries anything funny.

When Mark does pounce, Donghyuck still doesn't see it coming.

They fall onto the platform, the hybrid sat on Donghyuck's hips, hands pushing down on Donghyuck's shoulders.

"I'm not a kid!" Mark growls, breath washing over Donghyuck's face.

Donghyuck coughs, having his breath knocked out of him.

"I'm ten years... older than you, Mark," Donghyuck manages to get out, untensing to look up at Mark's scowling face hovering over him. "Sometimes… I can't help… but see you as anything else… but a kid."

Mark's frown deepens, before asking: "Will a kid do this?"

"Do wha--"

Donghyuck doesn't manage to finish his question because Mark slams his lips against Donghyuck, his tongue immediately asking permission for entry.

 _OH FUCK_ , Donghyuck's mind shrieks in sudden panic. His body doesn't listen, losing the strength to resist and letting Mark in.

He lets out a whimper when he feels his charge's tongue sweep around his mouth, and hears Mark's responding growl when Donghyuck reciprocates.

"I know, Hyung," Mark whispers against Donghyuck's lips when he pulls back a bit to let his handler breathe.

"I know how you look at me sometimes," Mark continues, rubbing their cheeks together, before snuffling against Donghyuck's face and neck. "I know you don't just see me as a kid, or as a work responsibility when you're monitoring my training or tests and I don't have my shirt on."

"I could just be… looking at Jeno… shirtless next to you, though," Donghyuck teases, a grin making its way onto his lips even as he's breathless from their kiss. It's really not the time to tease, but he's out of his depth, being exposed by Mark like this. He needs time to regroup and get his breathing and pulse back in order.

Mark lets out a snort as he smirks. "As if you would with how Jaemin and Renjun already called dibs on Jeno the first time y'all met."

Donghyuck huffs out a small laugh, head lolling in defeat. "Yeah, I'm not a homewrecker."

Their eyes meet, before something clicks in Donghyuck's brain.

"Is that why you fucking tried to crush Jeno to a pulp earlier?"

A beautiful flush spreads across Mark cheeks, up to his ears, and down his neck. Donghyuck's eyes widen.

"Fuck, is that why you've been cranky the past few days?" Donghyuck demanded, an incredulous smile taking over his face. "Was little Markie jealous that darling Nono's been spending time around me?"

At Mark's growl, Donghyuck, cracks up.

"You know Nana and Junnie already have his dick all tied up for them, right?" He asks, cackling again when Mark's nose crinkles in distaste. Mark dislikes hearing his handlers and squad members cursing, but he himself won't hesitate dropping a _shit_ or a _fuck_ when he screws up.

"Now, lemme up, kid," Donghyuck says, bucking up to try and dislodge Mark. "You have a test to do."

"I'm not a kid!" Mark growls in reply, grinding back in his seat to stop Donghyuck from moving.

Donghyuck feels a bolt of pleasure strike down his spine.

"I won't do that if I were you," he warns the younger, face carefully blank to not make it obvious how he much he liked what Mark is doing.

He realizes it's a moot point when Mark sniffs and smirks down at him.

"Why not, Hyung?" Mark returns, licking at his lips. _Like a predator locked on its prey_. "You smell like you liked it; lots of nice pheromones in the air that I can practically taste it on my tongue."

Without warning, Mark leans down and kisses Donghyuck again. It's more than before: deeper, longer, sweeter; just _more_.

Mark's hands start to wander, from Donghyuck's shoulders, down his chest to squeeze briefly at his chest, sweeping down his sides, to his belt buckle.

"Fuck, Markie," Donghyuck gasps, shivering from the caresses. "Don't."

"Why not?" Mark is growling, deep within his throat, his scowl returning.

"I'm your handler, Mark," Donghyuck says, hands going to his fly to catch Mark's. He squeezes them comfortingly. "Admin's not gonna like me if I let you."

"I'm gonna lose my shit if they try to take you from me," Mark rumbles, his right eye turning golden as his mutations manifest physically in response to his emotional state.

"They're just trying to look out for you." Donghyuck tries to settle him by moving a hand to cup his jaw.

Mark grasps the hand on his face, not wanting to let go. "I want you to look out for me!"

"They're going to think I did something to you," Donghyuck warns.

Yes, he admits, he's wanted Mark the moment he realized he wants to monitor all of Mark's training sessions personally less because of scientific reasons and more because he wants to see Mark do superhuman feats without his shirt on, all of his compact muscles all sweaty and on display.

He expects Mark to give up, or maybe whine out another flimsy excuse. He's not expecting what Mark says next.

"Dad can vouch for you, Hyung," Mark purrs, rubbing his face against Donghyuck's hand. "He can tell them you didn't do anything to me."

Donghyuck's eyes narrow. "What the fuck have you been telling Dr Minseok, twerp?"

"Nothing," Mark hedges. "But he kept asking me why I suddenly seem to always lose my shirt during training."

He cringes when his canines suddenly drop. "And why, when we were at the pool on you guys' first monthsary, my teeth came out when you took your shirt off to swim."

"Oh, Markie likes tits, then?" Donghyuck latches on, not being able to stop himself from teasing Mark when the opportunity arises.

"I like _your_ tits," Mark shoots back, growl returning to his voice. "They look puffy and squishy."

"Insulting me won't make me want to put your dick in my ass, brat," Donghyuck retorts, but he's smiling.

"So you've had a crush on me that long?"

"I smelled your arousal the first day we met before Dad said I was 21," Mark replies, face unimpressed. "What do you say about that, Hyung?"

"Is that why you kept stretching your jaw with your mouth open the day we met? A fucking Flehmen response?" Donghyuck asks, looking up at Mark in surprise. "You were sniffing me for pheromones?" At Mark's embarrassed nod, Donghyuck flops his head back onto the ground.

"I haven't gotten laid properly since I got employed here if I'm seriously considering letting you near my ass right now," Donghyuck sighs.

Mark smirks and grinds down on him again, and Donghyuck lets out a groan. "That's unfair, brat."

"You think that's unfair? I'll show you unfair."

Mark gets off him and the platform, but doesn't go far. He moves to kneel between Donghyuck's legs and pulls him by the hips further onto the edge so his ass hangs off the platform, his thighs braced over Mark's as the liger hybrid grinds against his ass.

"Fuck, Mark!" Donghyuck hisses, hands flying to Mark's face to pull him down for a kiss.

He can't believe he's doing this.

He's supposed to be Mark's guardian, and yet, here he is, about to let his charge into his pants. It's definitely, absolutely irresponsible and unprofessional and probably morally gray with their ten-year age gap, but one of Mark's hands drift up to twist one of Donghyuck's nipples as he grinds his filling, large cock against Donghyuck's ass, and it's all he can do to keep breathing.

Donghyuck keeps muttering curses under his breath as he tries to pull off his pants off. Mark gets the idea and helps him, pulling off Donghyuck's slacks, boxer briefs, and loafers off on one hard tug, leaving his lower half naked save his low-cut socks.

Mark stuffs a hand in his joggers' pocket and pulls out something Donghyuck doesn't see properly. He then unties his joggers and pulls them low enough around his thighs to have his cock pop up, the waist band going just past his balls.

Donghyuck stares at Mark's cock. He'd speculated and hoped, but he hadn't been able to confirm if Mark's cock had the stereotypical feline penile spines until now. He never thought he'd be into this kind of shit, but the more you know, he guesses. God, those would probably make his insides feel _so good_ later on.

Donghyuck lays back down as he pulls his shirt and tucks it under his chin.

"Better make it quick. Markie, before I change my mind."

In response, the click of a bottle rings in the air, and Donghyuck realizes that what Mark pulled out from his pocket was probably a bottle of oil or lotion to use as lube.

"You little fucker, did you plan this?" Donghyuck demands, sitting back up to look at Mark's guilty face.

He loses strength in his arms and falls back down when Mark inserts two slick fingers into him.

"Maybe?" Mark admits, dragging his fingers in and out to spread the lubricant, before hunting around for Donghyuck's prostate. "I know you usually jack off on your day off, which was yesterday, and I'm pretty sure I saw you limping a bit while you were looking for me."

"Fuck, you little stalker, I can't believe you know this," Donghyuck lets out a little incredulous laugh, before letting out a pleasured moan. "You're lucky I was in the mood to ride my dildo in the shower today."

 _"Fuck_ ," Mark growls, before pulling his fingers out and slamming his spiny hybrid cock deep into Donghyuck's ass.

Donghyuck gasps, feeling how Mark's thick cock splits him open, Mark's spines raking against his walls every time Mark pulls back to push into him again.

He pulls Mark back down for a kiss, and Mark redoubles his efforts to rearrange Donghyuck's insides as their tongues battle it out.

Suddenly, Donghyuck's communicator crackles to life.

'Ironman _? It's_ Hulk _. Where the fuck are you?_ '

Holy fuck, it's Renjun. Donghyuck is dead if he ignores him.

He tries to stop Mark fucking into him, just until he finishes talking to Renjun, but the hybrid won't hear of it. He wraps his arms around Donghyuck's middle and keeps his pace, tucking his head against his handler's collarbones.

"This--This is _Iron-Ironman_ …" Donghyuck stutters out, trying to keep his composure.

' _You found him?_ ' Comes Renjun's impatient demand.

"Yeah… Yeah, I-ah! I've got-- I've got him," Donghyuck replies through grit teeth as Mark keeps hitting his prostate spot on.

' _Why do you--_ ' Renjun cuts off, before gasping.

' _Disgusting,_ ' he suddenly hisses. ' _The moment I see you, I'm gonna kill you. Over and out._ '

"Fuck, he knows," Donghyuck ekes out. This seems to spur Mark on, because he curses before going back up to meet Donghyuck's lips in a deep kiss.

They're too wound up to make it last. When Mark pulls away to dive down to Donghyuck's chest, teething at his nipples with those sharp canines, Donghyuck can't stop the wave of pleasure of his orgasm taking over him. He spills across both their stomachs, and Mark thrusts even faster and deeper than Donghyuck thought was possible.

Mark cums deep inside Donghyuck's guts, the way his spikes drag against his insides feeding into his orgasm.

When they both catch their breaths, Mark pulls out slow and steady. His spines have softened enough that they hopefully won't deal Donghyuck more damage than they already have.

Mark kneels against the edge of the platform, pulling Donghyuck up to sit on his slanted thighs. Mark rubs his face against Donghyuck again, and the older lets him, hands caressing the younger's dyed red hair fondly.

"Thank God you have a huge shower and a locker room," Donghyuck rasps against Mark's lips, stealing a quick kiss.

When they make their way out of Mark's habitat, they see their entire handling team camped out on the entrance, sitting on the floor or leaning on the walls in wait.

The moment Renjun catches sight of them, he gets up from his place on the floor next to Jeno and Jaemin to charge out at them accusingly.

"I can't believe you!" He says, voice shrill. _"_ He's a _child_! _"_

"He's legal," Donghyuck replies, trying to calm his colleague. "He's twenty-one."

"He's ten years younger than you!" Renjun continues, reaching a hand over to grab Donghyuck.

Mark cuts in between them suddenly, his right eye burning gold, canines out as he growls at Renjun. Jisung and Chenle scramble to pull Renjun back away from Mark as Jaemin helps Jeno up from sitting on the floor. Donghyuck looks back helplessly at them from behind the hybrid.

"Step away, Ge," Mark warns, voice gravelly. "I don't want to hurt any of you again."

As the rest of them keep their distance, Mark finally deems everything safe, and he returns back to normal. He's clear-headed enough that he finally looks somewhat sheepish.

"Sorry."

"What are we telling Dr Kim?" Chenle asks, eyes narrowed. Donghyuck knows his brain is running countless speculations by now.

"He kinda already knows?" Mark offers.

Renjun rolls his eyes in exasperation. "God, whatever."

He turns around and latches onto Jeno's arm that wasn't already held by Jaemin.

"Hyuck's not the only one who's going to get dicked down today," he says, pulling Jeno, and by extension Jaemin, back inside Headquarters.

"Jisung, reschedule your test to another day, because Jeno and Jaemin won't be able to move properly tomorrow."

"Hyung, you're gross, too," Jisung whines behind them, Chenle laughing next to him as they follow the three inside.

"So, what now?" Donghyuck says. He's got Mark wrapped around him as they stay behind at the entrance to Mark's habitat.

"I'm gonna ask Dad if he can be the one to tell the Higher Ups about the status update," Mark sighs out, obviously not thrilled with the absolute clusterfuck informing Admin about them will be. Donghyuck pets at his head to try and keep him calm.

"What about your hyungs?" Donghyuck asks, referring to Mark's squadron. "Are you going to tell them about us?"

"Oh, they definitely know I like you," Mark cringes, curling deeper into Donghyuck's side. "They're gonna be insufferable, oh my God!"

"Better clean up the stage now before you guys do any sparring or practicing tomorrow, then," Donghyuck says, pulling Mark up to leave a kiss on his forehead before stepping away and following his team inside.

"I'll be waiting in my room once you're done, okay?" Donghyuck calls over his shoulder, hand waving goodbye. "I need you to drill me into my mattress before your curfew, baby, so chop-chop!"


End file.
